That lane may once have connected the fort's interior to the haggard of a nearby farmhouse, a word that here means the yard or enclosure used for storing hay and farm equipment. The suggestion is quietly odd: an ancient enclosure, probably early medieval in origin, folded into the working life of a nineteenth-century farm, its prehistoric geometry repurposed as a practical corner of an agricultural holding.

Ringforts are circular or roughly circular enclosures defined by an earthen bank and, sometimes, an outer ditch called a fosse. They were built and occupied mainly between the sixth and tenth centuries and served as farmsteads for families of some local standing. The Killynan example, as recorded on that 1837 map, measured approximately 40 metres along its northeast-southwest axis and 33 metres across from northwest to southeast, with the straight southern side formed not by original construction but by a field fence. By 1981, when the monument was formally described, it had contracted considerably in visible terms, reading as a raised semi-circular area of only around 15 metres by 11 metres. The denuded bank and traces of the fosse were still most legible at the northern arc; the southern portion had been cut through by the same field boundary that had long since claimed that edge. Boulders scattered across the interior suggest that the underlying bedrock lies close to the surface, which may partly explain why the bank has worn so low. More recently, no trace of the earthwork has been identifiable on aerial photography at all, meaning the site now exists more convincingly in documentary records than in the landscape itself.